26 LCD CONTROLLER (LCDC)
26-16
Seiko Epson Corporation
S1C33L26 TECHNICAL MANUAL
1-bpp mode (black & white, 2 colors, or 2 gray levels)
In 1-bpp mode, each bit in the VRAM corresponds to one pixel. The bit data represents the brightness (0 or
1) of the pixel when the look-up table is bypassed or an LUT entry number (0 or 1) when the look-up table is
used.
(7,0)
(0,0)
D0
(15,0)
(8,0)
VRAM
Display start address
Byte address offset
1 bit / 1 pixel
When LUT is bypassed
When LUT is used
LUT entry number
b7 b6 b5 b4 b3 b2 b1 b0
(x, y)
+0
+1
LCD
I/F
LCD
I/F
LUT
entries 0 and 1
FPDAT signals
FPDAT signals
Brightness data
in the specified
entry
5.5.1 VRAM Data Format in 1-bpp Mode
Figure 26.
Example
VRAM start address: 0x10000000
Screen width:
320 pixels
LUT:
Bypassed
LCD characteristics: Data = 0
→
Low LCD brightness
Display image
Coordinates
(0, 0)
320 pixels
VRAM data
Address
0x1000 0000
0x1000 0028
0x1000 0050
:
0xdf ..........
0x83 ..........
0xdf ..........
:
40 bytes / line
Note) Display may be inverted depending on the LCD panel used.
5.5.2 Example of VRAM Data in 1-bpp Mode
Figure 26.
2-bpp mode (4 colors or 4 gray levels)
In 2-bpp mode, each 2-bit data in the VRAM corresponds to one pixel. The 2-bit data represents the brightness (0
to 3) of the pixel when the look-up table is bypassed or an LUT entry number (0 to 3) when the look-up table is
used.
(3,0)
(0,0)
D1 D0
LCD
I/F
LCD
I/F
LUT
entries 0 to 3
(7,0)
(4,0)
VRAM
Display start address
Byte address offset
2 bit / 1 pixel
When LUT is bypassed
When LUT is used
FPDAT signals
FPDAT signals
LUT entry number
(x, y)
MSB LSB
Brightness data
in the specified
entry
+0
+1
(11,0)
(8,0)
+2
(15,0)
(12,0)
+3
b[7:6]
...
b[1:0]
5.5.3 VRAM Data Format in 2-bpp Mode
Figure 26.